As the basic building blocks of the nano-devices, nano-scale materials carry the information transport, storage and other important functions.
The interest in the trend to reduce the dimensions of these devices in the semiconductor and information industries has given rise to a necessity for developing techniques for studying microstructure and the size effects on the mechanical strength and charge transport properties of individual functional nanostructure under external stress field and electric field.
Transmission electron microscopy (TEM) is a powerful tool for characterizing the micro-structures of solid state materials in the field of nano-science and nanotechnology. TEM grid is used to support the detected samples, which is usually Cu grid 3 mm in diameter with thin carbon film coatings. But at present the TEM grid is effective only for the static testing, and not for in situ manipulation and dynamic testing at the nanoscale even to atomic scale level.
In situ TEM experiments provide direct visualization and description of the events as they happen and give qualitative information about the structure-property-processing relationships. These knowledge are vital to not only the design and functional the nanodevices and but also the reliability and service.
Several approaches have been studies for in situ electron microscopy manipulating, measuring and imaging the structure-property relationships of individual nanotub or nanowire.
One technique is described in “Physics review letters, vol. 94, 236802,2005” by Z. F. Ren. They combined the scanning tunnel microscopy probe with transmission electron microscopy, which revealed that the intrinsic properties of super plastic deformation of carbon nanotubes under electrifying state.
Another method for in situ electron microscopy testing one-dimentional nanostructure is reported in “Proceedings of the National Academy of Sciences, Vol. 102, No. 41, p. 14503-14508, 2005.” by H. D. Espinosa. They developed a microelectromechanical systems (MEMS) based testing unit for in situ TEM mechanical testing of nanotubes, nanowires and thin films.
The above mentioned methods integrated the scanning tunneling microscopy probe or MEMS unit with the TEM holder, thereby enabling simultaneous TEM and mechanical measurements, for investigating the relationship between microstructure and interaction of individual nanostructure. But installing these devices inside the TEM holder that causes the holder can tilt a small angle or only a single axis tilting because of the narrow pole-piece gap. However, atomic scale lattice resolution of a crystal is only achieved when a low-indexed zone axis of a crystal is precisely aligned parallel to the electron beam. This condition is difficult to fulfill in these in situ measuring systems that are subjected to mechanical manipulation influence during the experiments.